Please answer the following question clearly, thank you.

1.Quarterly party bookings at Terrace Events been recorded as follows.

a)Compute the seasonal quarterly indexes given the regression line: y= 3 + 4t YEAR Quarter t Yt y Ratio Quarters

2019 1 4

2 7

3 14

4 8

2020 1 5

2 3

3 10

4 6

b)Use the seasonal quarterly index to de-seasonalize the time series.

YEAR Quarter t Yt SQL Seasonally adjusted time series

2019 1

2

3

4

2020 1

2

3

4

c) Use the regression line: y= 3 + 4t and the seasonal quarterly indexes to forecast Terrace Events' party bookings for all quarters of 2021.

YEAR Quarter t y SQL Forecast

2021 1

2

3

4